1. Field of the Invention
The present invention relates to ignitors for model rockets, and, more particularly, electrical ignitors for model rockets.
2. Description of the Related Art
Model rockets include a motor made from a solid propellant which is ignited to cause the model rocket to be propelled into the air. It is known to use an electrical ignitor to ignite the solid propellant. Such an electrical ignitor includes a pair of lead wires which are connected to a tiny printed circuit board. A nichrome wire forming a small loop at the distal end of the ignitor includes opposing ends which are soldered to the printed circuit board. Because of the physical position of the nichrome wire at the end of the ignitor, the ignition event (i.e., combustion of the solid propellant) occurs at the end of the ignitor. A problem with this is that the ignitor may be shot out of the rocket by the ignition event. This is similar to the movement of a piston in a cylinder.
Another problem with a conventional electrical ignitor is that the nichrome is an alloy of nickel, chrome and iron with a melting point of about 2500 degrees Fahrenheit. The nichrome wire cannot be soldered with a regular rosin core solder. A special flux with hydrochloric acid must be used, which may pose health concerns. Moreover, such a solder connection is generally mechanically weak. Yet another problem with using nichrome wire is that its melting point is high enough that it may continue to drain the battery connected to the ignitor after the rocket launch has been completed.
What is needed in the art is an electrical ignitor with an element wire that is solderable and does not drain an attached battery after ignition. The ignitor should not be propelled out of the rocket by the ignition event.